In furnace systems exceeding 15,000KW, we will utilize parallel resonance power supplies. Compared to series resonance power supplies, parallel resonance power supplies offer higher safety in high-power applications. Our unique parallel resonance design ensures full rectification when the power exceeds 40%, high power factor, and smaller higher-order harmonics. Compared to traditional parallel power supplies, it offers greater benefits.
Our unique design ensures a high startup success rate. Even under high-power conditions, we maintain the coil design voltage within a reasonable range, guaranteeing the safety of the equipment. The high-power parallel power supply can form a one-to-one melting system and can also select the furnace body through an external high-capacity pneumatic switching switch, allowing for easy implementation of a one-to-two switching melting system or a two-to-three switching melting system to meet various different application needs.
The multi-pulse design of 12-pulse and 24-pulse power cabinets further reduces higher-order harmonics. The unique rectifier trigger board design ensures current balance between phases, while implementing soft start to prevent power surges and quickly cutting off power in the event of a fault.
All signal transmission is achieved through optical fibers, boasting strong anti-interference capabilities and greater system stability. All components of the parallel resonant medium-frequency power supply are installed in a sealed cabinet. The copper busbars and tubes within the power cabinet utilize domestic renowned brands, with the busbars being sandblasted and passivated, adhering to standardized production processes. The layout of the components in the power cabinet is rational, facilitating maintenance and cable management. Maintenance personnel can easily access all repair points.
The power cabinet is equipped with a melting management system. The PLC and human-machine interface form a convenient-to-operate melting management system, featuring: automatic furnace drying, cold furnace startup, fault diagnosis, fault information display and storage, operational information display, and system status display, etc. A sealed isolation control room is arranged above the front door, housing the main control panel, feedback panel, and control power units, allowing for easy observation of the main control panel signals. The isolation control room does not require additional cooling. The main electronic components of the power cabinet are cool, and the temperature rise inside the cabinet during operation will not affect the isolation control room. Additionally, the selection of all electronic components on the electronic control circuit boards within the isolation control room is carried out according to high-temperature ratings.
Equipped with a fully functional incoming line air switch protection system. The quick-acting fully functional circuit breaker (air switch) is installed on the front of the power supply, operated by an electrically operated mechanism, with a 24V under-voltage coil providing interlock protection. It also features overcurrent protection; upon overcurrent occurrence, it trips to protect the incoming line power from supplying the power cabinet. The bridge rectifier section converts AC to DC, providing a stable DC platform for the inverter section. Capacitors are installed in a fully enclosed capacitor cabinet, made of high-strength cold-rolled steel plates. It is also equipped with differential current and DC injection type leakage furnace alarm circuits, indicator lights, leakage current meters, and detection control circuits, etc. During normal operation, it continuously detects.
When the following conditions occur, shut off the power:
Metal penetrates through the furnace lining to the induction coil.
2. There is an excessive amount of moisture in the refractory lining.
3. Some electrical components exhibit low resistance to ground.
The entire coil is wound using oxygen-free copper tube, ensuring that the differential current method and the DC injection-type leak furnace alarm circuit protect the entire coil, including both effective and cold coils. The differential current method is an electronic form of protection that is fast-acting, allowing for rapid response when ground fault occurs in the output circuit. The DC injection-type leak furnace alarm is a non-electronic form of protection that is relatively slower, but it can still detect leaks when the power cabinet stops operating.
